Receiver arrangement



. Feb. 13, 1940.

HANS-WERNER STEINHAUSEN 2,190,436

RECEIVER ARRANGEMENT Filed June 8, 1938 Egi INVENTOR HAA/S-A ERIVIE'IQy/mmusz-w ATTORNEYS Patented Feb. 1940 um n stares Hans-WernerSteinhausen, BerIimGermany, as-

signor to Tclefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H.,Berlin, Germany,

'"j I a corporation of Germany ,Application June 8, 1938, Serial No.212,423 i I In Germany June 9, 1937 signedtothe same assignee as thepresent application, his proposed in connection with a receivingarrangement to'terminate the double wire line connected to the antennawith a resistor having the-value" of the wave resistance, ifel,

surge impedance and across a "filter .pervious only to' 'highfrequencies,- whereby said resistor'is chosen for the high frequenciesfor which the capacitive resistance of the double" wire lineis lowerthan-its wave resistance. Furthermore, in this case the antenna ismatched with a resistance that is higher thanthe wave resistance,

case of broadcast waves and long waves since the matching i. e.'theproportion between the re- 5 sistance of the cable or double wire lineand the antenna resistance is a poorone. The an tenna resistance beingprimarily a capacitive resistance, will then be higher than in the caseof short" waves so that it is 'high' ascompared with the wave resistancewhereby only a small part of the total antenna voltage appears there.-at. For this reason according to the patent the terminal resistor isrendered ineffective in the case of broadcast waves and long waves and'for these wave ranges the antenna is accurately or approximatelymatched with the capacitive resistance of the cable. .Sincein this caseboth the antenna resistance and the cable resistance are capacitive. theproportion between both and hence the matching has always themostfavorable value throughout the broadcast wave range and long waverange.

With the present invention the short wave reception in such a receiving"arrangement is improved. in a simple manner. Herein lies an advantagein view of the fact that in the receiver as well as in an antennaamplifier eventually present the short waves are detrimentally resistoris efiective and whose secondary winding then differ appreciably fromthe ratio 1:1.

4 Claims. (01. 178-44) According -to U. 's; Patent No. 2.112320, as-"'terminal resistor and the filter are joined, while has one endconnected to the point at which the with the double wire line Lacross atransformer more especially withthe capacitive resistance of the doublewire line. The terminal resistance whose value is that of the waveresistance of the line is designatedby W. This terminal resistor isconnected in series with a condenser C which in this caseassumes thetask of the filter-since K. 'On the other wave ranges the main voltageis developed across the condenserC so that the series connection'of theprimary and secondary.

winding of the transformer K solelyhas' the 7 effect of a lead-in. Infact the" short wave transformer has buta few windings The output isconnected either to one or several receivers,

or to an antenna amplifier from which the energy is passed to thereceivers across a second double wire line.

In the example of construction according to Figure 2 no transformer isprovided between the antenna and the double Wireline. This conditionexists when using the principle of the above patent in the casein whichthe capacity of the cable is of the order of the antenna capacitybecause in this case a transformer is no longer required since itstransformation ratio does not This condition exists if for instance arod antenna has a capacity of mi. while a rather short cable need simplybe used for instance of a length of 7 m. and having a capacity of 200mi.

when figuring with a capacity of 30 mi. per

meter. Since such a cable still has a length requiring termination ofthe cable onthe short wave range 0/; of a wave of 28 m. being equal tothe length of the cable), it would be necessary to provide an antennatransformer for the broadcast waves and long waves unless the idea ofthe above patent is used. In fact, if at a wavelength of 60 m. thecapacitive resistance of thiscable is ohms so that as regards value itdoes not differ from the usual value of the wave resistance of ohms, thecapacitive resistance of this cable is already 50 ohms at a wavelengthof 200 m., and 5000 ohms at a Wavelength of 2000 m. Therefore, in caseof a fixedly connected. terminal resistor and without the use of anantenna transformer, i. e., without utilizing the idea of'the abovepatent there would be obtained in the range between 200 m. and 2000m. avoltage division and hence a loss of 1:3 up" to 1:30.

In the case of the short cable length assumed and in the circuitaccording to Figure 2 considered more especially for arrangements. withantenna amplifiers, there is obtained a more uni;

form efficiency than without short wave transformer, since thedifference is. then especially large' between the capacitive resistanceof the cable on the broadcast wave rangeand long. Wave range and theWave resistance or match ing with the input of the amplifier in casewofIn fact, an additional voltagein-' so thatan additional transformerbetweencable and antenna amplifier would for these wave ranges not bringabout'a particular advantage. Nevertheless itwould be possible'inFigure2 and especially in Figure. Iito place in parallel to the outputterminals one or several parallel transformers: for the broadcast wavesand long waves eventually by connecting chokes aheadthereto.

1. In a receiving system for receiving waves over longandshort waveranges, an'energy collector; a: two. conductor transmissionlineconnected-at one end tothe: collector, said transmission linehaving. a: length which is at leastcomparable-to awavelength at a shortwave range,- awtransformer having a primary winding and-asecondary.winding, a condenser and an impecb ance meansconnected in seriesacross'the other endoi the. line, said impedance 1 means including; saidprimary winding and having substantially the same value as. the surge;impedance of the line, a pair of terminals for connecting the 'line to autilization device, and means including the secondary of saidtransformer and said con-' denser in series for connecting said two.termi-' nals together. 2. A receiving'system for receiving waves overawid'erange of frequencies;comprisjing ian energy j collector, atwo-conductor transmission line coupled at one end to the collector,said transmis- I sion line having av length comparable to a wave lengthhaving the range but small in length compared to a wave lengthcorresponding to the lowest frequency of said range, a terminatingresistance and a con- I I,

denser connected in series across the line, said terminating resistancehaving substantially the highest frequency of said same-svalue as'th'esurge impedanceof the line,.

a short wave transformer having a primary windinganda secondary winding,a pair of termi-,

nals adapted to be connected to a utilization de vice, meansjforconnecting thepri-maryawinding' of said transformer across Isaidterminatingrre 'sistor, and: a connection between said twoterminals, said connection including the secondary. of said. transformerandgsaid condenser m series..

. 3. Anqinput'circui-t for a shortwave'andglong wavereceiver-comprisingi,an: antenna; a: trans-v ission line having one .endcoupled. to the antenna; the other 1 end of the transmissionvline havinga-- filter: constituted by a resistance and a capacity connected acrossthe lineandi awhigh frequency transformer, the primary of which isconnected across the filterresistance andthe secondary of whichtogetherwi-ththe filter conev adapted to be ceiver 4; A circuitfor-coupling ashort wave'and long Wave receiver to anantenna, comprisinga trans-. mission. linehaving one end coupled to the- -an.- tenna, afilter constituted by a. series resistance andacapacity connected acrossthe transmission line at thaother end, a high'frequencytranse former haing its primary connectedacross. the filter resistance, a pair. ofoutput terminals adapt ed. to be connected; to. the inputfof thereceiver; said output terminals having connectedbetween them thesecondary ,otjthe highfrequentyiransformerand the capacityofthe'terminating filter.

